Highly soluble tris- (2, 3-epoxypropyl)- isocyanurate and method for producing same

Abstract

There is provided an epoxy composition which has difficulty in precipitating a crystal during storage, is homogeneous and can be stored for a long period; and a cured product of the composition having excellent transparency, heat resistance, and light resistance can be obtained on curing. An α-type tris-(2,3-epoxypropyl)-isocyanurate crystal including β-type tris-(2,3-epoxypropyl)-isocyanurate in the crystal in a ratio of 2% by mass to 15% by mass. A method for producing the α-type tris-(2,3-epoxypropyl)-isocyanurate crystal including step (i) separating β-type tris-(2,3-epoxypropyl)-isocyanurate contained in a tris-(2,3-epoxypropyl)-isocyanurate solution from the solution as a solid to obtain a crystal with an increased content ratio of α-type tris-(2,3-epoxypropyl)-isocyanurate.

1 . An α-type tris-(2,3-epoxypropyl)-isocyanurate crystal comprising:
 β-type tris-(2,3-epoxypropyl)-isocyanurate in the crystal in a ratio of 2% by mass to 15% by mass. 
 
     
     
         2 . The α-type tris-(2,3-epoxypropyl)-isocyanurate crystal according to  claim 1 , wherein β-type tris-(2,3-epoxypropyl)-isocyanurate is contained in the crystal in a ratio of 2% by mass to 10% by mass. 
     
     
         3 . The α-type tris-(2,3-epoxypropyl)-isocyanurate crystal according to  claim 1 , wherein the crystal has a particle diameter of 1 μm to 500 μm. 
     
     
         4 . A method for producing the α-type tris-(2,3-epoxypropyl)-isocyanurate crystal according to  claim 1 , the method comprising:
 (i) separating β-type tris-(2,3-epoxypropyl)-isocyanurate contained in a tris-(2,3-epoxypropyl)-isocyanurate solution from the solution as a solid to obtain a crystal with an increased content ratio of α-type tris-(2,3-epoxypropyl)-isocyanurate. 
 
     
     
         5 . A method for producing the α-type tris-(2,3-epoxypropyl)-isocyanurate crystal according to  claim 1 , the method comprising:
 (i) separating β-type tris-(2,3-epoxypropyl)-isocyanurate contained in a tris-(2,3-epoxypropyl)-isocyanurate solution from the solution as a solid to obtain a crystal or a solution with an increased content ratio of α-type tris-(2,3-epoxypropyl)-isocyanurate; and 
 (ii) extracting β-type tris-(2,3-epoxypropyl)-isocyanurate contained in the crystal or the solution obtained in (i) with a solvent to obtain a crystal with an increased content ratio of α-type tris-(2,3-epoxypropyl)-isocyanurate. 
 
     
     
         6 . The method for producing according to  claim 5 , wherein the extraction in (ii) is carried out by using a heated solvent, a solvent at normal temperature, or a cooled solvent. 
     
     
         7 . The method for producing according to  claim 4 , wherein the solvent for the tris-(2,3-epoxypropyl)-isocyanurate solution used in (i) is methyl ethyl ketone, acetone, acetonitrile, ethyl acetate, or epichlorohydrin. 
     
     
         8 . The method for producing according to  claim 5 , wherein the solvent for extracting β-type tris-(2,3-epoxypropyl)-isocyanurate in (ii) is methyl ethyl ketone, acetone, methanol, ethanol, water, or isopropanol. 
     
     
         9 . A method for producing the α-type tris-(2,3-epoxypropyl)-isocyanurate crystal according to  claim 1 , the method comprising (A), (B), and (i′):
 (A) generating an epichlorohydrin adduct of cyanuric acid by reacting 1 mol of cyanuric acid with 5 mol to 180 mol of epichlorohydrin and subsequently carrying out dehydrochlorination to obtain a reaction solution containing tris-(2,3-epoxypropyl)-isocyanurate; 
 (B) adjusting a solid content concentration of the reaction solution containing tris-(2,3-epoxypropyl)-isocyanurate obtained in (A) to 10% by mass to 50% by mass; and 
 (i′) separating β-type tris-(2,3-epoxypropyl)-isocyanurate contained in the tris-(2,3-epoxypropyl)-isocyanurate solution obtained in (B) from the solution as a solid to obtain a crystal with an increased content ratio of α-type tris-(2,3-epoxypropyl)-isocyanurate. 
 
     
     
         10 . A method for producing the α-type tris-(2,3-epoxypropyl)-isocyanurate crystal according to  claim 1 , the method comprising (A), (B), (i′), and (ii′):
 (A) generating an epichlorohydrin adduct of cyanuric acid by reacting 1 mol of cyanuric acid with 5 mol to 180 mol of epichlorohydrin and subsequently carrying out dehydrochlorination to obtain a reaction solution containing tris-(2,3-epoxypropyl)-isocyanurate; 
 (B) adjusting a solid content concentration of the reaction solution containing tris-(2,3-epoxypropyl)-isocyanurate obtained in (A) to 10% by mass to 50% by mass; 
 (i′) separating β-type tris-(2,3-epoxypropyl)-isocyanurate contained in the tris-(2,3-epoxypropyl)-isocyanurate solution obtained in (B) from the solution as a solid to obtain a crystal or a solution with an increased content ratio of α-type tris-(2,3-epoxypropyl)-isocyanurate; and 
 (ii′) extracting β-type tris-(2,3-epoxypropyl)-isocyanurate contained in the crystal or the solution obtained in (i′) with a solvent to obtain a crystal with an increased content ratio of α-type tris-(2,3-epoxypropyl)-isocyanurate. 
 
     
     
         11 . The method for producing according to  claim 10 , wherein the extraction in (ii′) is carried out by using a heated solvent, a solvent at normal temperature, or a cooled solvent. 
     
     
         12 . The method for producing according to  claim 9 , wherein the solvent for the tris-(2,3-epoxypropyl)-isocyanurate solution used in (i′) is epichlorohydrin. 
     
     
         13 . The method for producing according to  claim 10 , wherein the solvent for extracting β-type tris-(2,3-epoxypropyl)-isocyanurate in (ii′) is methyl ethyl ketone, acetone, methanol, ethanol, water, or isopropanol. 
     
     
         14 . A curable composition comprising:
 the α-type tris-(2,3-epoxypropyl)-isocyanurate crystal according to  claim 1 ; and   a carboxylic acid anhydride in a ratio of 0.5 molar equivalent to 1.5 molar equivalent relative to 1 molar equivalent of the crystal.   
     
     
         15 . A liquid curable composition comprising:
 the α-type tris-(2,3-epoxypropyl)-isocyanurate crystal according to  claim 1 ; and   a liquid carboxylic acid anhydride in a ratio of 0.5 molar equivalent to 1.5 molar equivalent relative to 1 molar equivalent of the crystal.   
     
     
         16 . A curable composition comprising:
 the α-type tris-(2,3-epoxypropyl)-isocyanurate crystal according to  claim 1 ; and   a cationic curable compound in a ratio of 0.2 molar equivalent to 5 molar equivalent relative to 1 molar equivalent of the crystal.   
     
     
         17 . A liquid curable composition comprising:
 the α-type tris-(2,3-epoxypropyl)-isocyanurate crystal according to  claim 1 ; and   a liquid cationic curable compound in a ratio of 0.2 molar equivalent to 5 molar equivalent relative to 1 molar equivalent of the crystal.   
     
     
         18 . A cured product formed by attaching the curable composition according to  claim 14  to a substrate and curing the curable composition by heating or light irradiation. 
     
     
         19 . The cured product according to  claim 18 , wherein the attaching to the substrate is carried out by application, filling, adhesion, or impregnation.